Types of real conditional
1. Zero conditional
Use cases: In English, we often use zero conditional statements when we want to talk about facts.
To explain things that happen regularly in daily life.
To explain things which are true.
To explain one thing depends on another.
To explain one thing is the result of another.
Structure: All the conditional structure has two parts the condition and the result of that condition. For zero conditional, the verb in both parts must be in the present tense.
To construct the zero conditional statements, for the condition/situation part we can use if/when/every time/whenever
"If" and "When" implies that how frequent the condition happens. you can use "if" to show that condition/situation happens less frequently, whereas "when" is used to show situation happens more frequently.
"whenever" and "every time" are useful when you want to say that certain results always happens after the condition.
Eg. : If I have a day off from work, I usually go to the Cinema. [Having a day from work happens seldom, so using "If" is the correct structure.]
Eg. : When John goes to his favourite restaurant, the waiters greet him by his name. [Using "when", this sentence implies that John goes to the restaurant often.]
Eg. : Whenever/every time I go for Avenger's movie, the cinema is (always) fully occupied. [This sentence implicitly adds (always), though not said/written because we used "whenever/every time".]
These same sentences can also be written/said in reverse by changing the position of condition and result.
Eg. : I usually go to the Cinema if I have a day off from work. [Having a day from work happens seldom, so using "If" is the correct structure.]
Eg. : The waiters greet him by his name when John goes to his favourite restaurant. [Using "when", this sentence implies that John goes to the restaurant often.]
Eg. : The cinema is (always) fully occupied whenever/every time I go for Avenger's movie. [This sentence implicitly adds (always), though not said/written because we used "whenever/every time".]
Note.: For writing, if you prefer to write condition/situation first then before starting its results "," must be added, otherwise, the sentence would become ambiguous.
2. First conditional
As we have seen above that zero conditional is used for real present situation/condition, whereas the first conditional is used when you want to talk about real future possibilities. Although both condition/situation and result say about the future, in English we use the simple present tense for explaining the condition and the future tense ("will/will not/going to/not going") to represent the result.
Structure: Condition - should start with "if" and must use the present tense by referring to future context.
For example - If I feel better tomorrow.
The result - I will go to college.
The full sentence can be in two possible ways,
If I feel better tomorrow, I will go to college.
I will go to college if I feel better tomorrow.
Both of the above sentences have exactly the same meaning only the position of condition and result are reversed, if the sentence starts with the condition then there must be a comma "," before starting result clause. If you have noticed in result clause we don't define time context because in the condition clause we have already mentioned it.
Note: Never use the future tense in the conditional clause, which starts with "if".(Eg. If I will feel better tomorrow)
**Alternative words for "if"
When should be used if the condition will definitely happen, in other words, you are sure that certain condition cannot be avoided.
Eg. When I retire from my job, I will leave in the countryside. [Working in a firm, I am sure that one day I will definitely retire from my work.]
As soon as should be used if you want to emphasize that result will follow immediately and definitely.
Eg. As soon as I get the expected band in IELTS, I will apply for MS in the UK.[This implies that I will apply for MS in the UK right away after I get required band score.]
Unless should be used if you want to say the probability is negative. In simple words "if not"
Eg. Unless you practice hard for IELTS writing, Your will not pass IELTS with flying colours.[This means that If you do not practice enough for writing, your chances to succeed is minimum.]
Structure for asking Questions with first conditional
We can ask Questions too using the first conditional. These Questions can be used when the result for the condition is possible and real. However, what if the result is not real or imaginary, well that one we will take a look at the subsequent article.
For Yes/No Question
Will + subject + base form of the verb + if/when/as soon as/unless + condition
Present form of to be + subject + going to + base form of the verb + if/when/as soon as/unless + condition
For example -
Will you call me as soon as you become free?
Are you going to play tennis if all of our friends come?
For Wh Questions
Wh question word + will + subject + base form of the verb + if/when/as soon as/unless + condition
Wh question word + present form of to be + subject + going to + base form of the verb + if/when/as soon as/unless + condition
For example -
What will you do if you become President of Country?
Which game are you going to play if all tennis courts are occupied?